Convective drying of spine gourd ( Momordica dioica ): Effect of ultrasound pre‐treatment on drying characteristics, color, and texture attributes

The present study aimed to explore the effect of ultrasound pre-treatment (USPT) and convective drying on the drying characteristics on the quality attributes of spine gourd (SG). The drying and rehydration characteristics were the best described by the Page model. USPT, as well as an increase in drying temperature, enhanced the drying rate of SG. USPT reduced the drying time whereas the sample dried at low temperature having higher rate of rehydration. The combined effect of USPT and drying temperature increased the moisture diffusivity of the sample from 8.55 × 10–10 to 2.63 × 10–9 m2/s. USPT of sample lowered the activation energy (34.57–29.43 kJ/mol) and increase in shrinkage. An increase in the drying temperature increased brittleness and crispiness but adversely affected the color. The higher retention of natural color favors the better acceptability of product dried at low-temperature drying (50°C) than control and others. Practical applications Limited studies have focused on the drying of spine gourd (SG). This study will add scientific data on the drying of SG with and without US. Dried slices can be directly cooked and break the barrier of seasonal availability. Dried crisp slices can be directly consumed as chips with spices.